Beginner’s Guide to Rifle Bullets: How They’re Made, Types and Uses

[ED: Here’s an old Ask Foghorn post that addresses a question we get frequently.]

Reader Randall writes:

While I’m not exactly a newbie when it comes to *using* firearms, I am a newbie gun *owner*. And now that I’m in the position of purchasing ammo, I’m finding things to be rather confusing when sorting out all there is to be had.

I think I’ve kind of figured out what I want to buy for my Springfield XD 9mm, but choosing ammo for my AR-15 is proving to be more daunting.

That’s a pretty wide-ranging question, so I’ll answer it in three parts. Part one is all about the different types of projectiles and there are quite a few. But first, in order to explain the different designations, a little about how bullets are made.

The vast majority of bullets are constructed of a solid lead core with a copper covering (called a “jacket”) that contains the lead. Lead is used because it’s an extremely dense, yet cheap metal, making it perfect for giving projectiles their weight while keeping the overall size small. Copper is used because it’s strong enough to keep the softer lead from de-forming, but soft enough to allow the gun’s rifling to “grip” the bullet.

Nick Leghorn for TTAG

The copper jacket starts out as a cup, having been cut from a long sheet. Through a process called “drawing,” the cup is lengthened and shaped to fit the profile of the projectile they’re making. These cups will eventually end up as jackets for 5.56 NATO rounds.

However, while this process is very efficient, it’s extremely difficult to actually get the metal to encase the entire lead core without any gaps. To keep production costs down, bullet manufacturers usually leave one end of the projectile open. Which end is open – and how that’s done – determines the classification of the projectile.

Nick Leghorn for TTAG

Here are three 150 grain .308 caliber bullets (a “grain” is a unit of bullet weight). And while they look very similar, the way in which they were manufactured is very different. The first projectile on the left is a “full metal jacket” (FMJ) round with a solid copper point. The other two are an open tip and a soft point bullet respectively, with openings in the copper at the tips of the projectiles.

Nick Leghorn for TTAG

Looking at the bases of the bullets we can see why they’re different. The “full metal jacket” bullet actually has an opening, but it’s at the bottom of the round. So what makes these bullets different? Let’s go over each one.

Full Metal Jacket (FMJ)

Nick Leghorn for TTAG

“Full Metal Jacket” or “FMJ” projectiles usually aren’t actually fully jacketed, but simply have a copper jacket covering the top of the projectile. Military FMJ ammunition is completely covered by a copper jacket (as per the Hague Conventions), which uses a more involved process than traditional civilian ammunition (but doesn’t alter the lethality of the rounds at all).

FMJ ammunition is manufactured so that the bottom of the original cup of copper becomes the tip of the bullet, producing a continuous jacket of copper over the top of the round. However, most civilian ammunition leaves the base of the lead core uncovered, as illustrated with the bullet on the left in the above images (the ones with the three bullets side by side).

FMJ ammunition is cheap to produce, and therefore is the traditional choice for use on the firing range. The uniform and aerodynamic design of the projectile also makes it the ideal choice for long range precision shooting.

However, that streamlined design means that it’s also more likely to penetrate a living target (like a human or an animal) and keep going out the other side, possibly injuring people further downrange and leaving only a small wound in the target. Therefore, for home defense and hunting it’s not advisable to use FMJ ammunition.

There are a couple variations of FMJ ammunition that can be recognized by their designations:

Round Nose (RN) — The tip of the bullet is rounded in a spherical shape, which is not particularly aerodynamic. This is used mostly in handgun ammunition and older rifle ammunition.

Boat Tail (BT) — The rear of the bullet is tapered to give it a more aerodynamic profile (the two bullets on the left in the images above). This is common in “match” grade rifle ammunition and long range target ammo.

FMJ ammo is the “default” ammunition style, and the only one where the jacket is drawn from the tip. Every other projectile uses a jacket that is drawn from the base, and the tip is usually designed to perform some sort of function.

Open Tip (OTM)

Nick Leghorn for TTAG

Again, with FMJ rifle rounds, the bottom of the cup becomes the tip of the bullet. With “open tip” bullets, the opposite is true — the bottom of the cup is the bottom of the bullet. While this covers more of the lead core than the FMJ projectile, it leaves a small opening at the tip of the bullet where the jacket was drawn together. Many people mistake this for hollow point ammunition, but the point is too small to work that way.

Open tip bullets are preferred by long distance shooters as the manufacturing process is more consistent than with FMJ projectiles. That leads to higher quality bullets and better performance at long distances. These projectiles are often referred to as “OTM” or “open tip match” to indicate that they’re held to a higher standard than regular range ammunition.

Due to the construction of the projectiles, open tip bullets perform nearly identically to FMJ projectiles when they strike the target.

Hollow Point (HP)

.357 Magnum round, Nick Leghorn for TTAG

For self-defense or hunting, hollow point bullets are the way to go. Following the same general manufacturing process as the “open tip” bullets, these projectiles feature an exaggerated opening at the front of the bullet. The idea is that this opening will force the projectile to expand upon impact with a target, dumping all of the energy of that round and creating a bigger wound with more “stopping power.”

Dan Z for TTAG

However, that gaping hole in the front of the bullet in self-defense rounds also creates an immense amount of drag as it travels through the air and negatively impacts its long range capabilities.

Hollow point ammo is the favorite choice for police officers and those who carry a concealed weapon for one simple reason: when a JHP round hits something, it stops. They don’t keep going like FMJ rounds can, potentially injuring people on the other side of the target.

Soft Point (SP)

Nick Leghorn for TTAG

While hollow point ammunition is great for handgun rounds at close range, when you’re hunting at longer ranges with a rifle you need a round with better ballistic properties. One of the first attempts to make a projectile with the accuracy of a FMJ bullet and the “terminal ballistics” (how well it does when it hits a target) of a hollow point round was the “soft point” bullet.

The main difference between a soft point bullet and an open tip bullet is that with the soft point, some of the lead core protrudes from the front of the round. This gives the bullet a more aerodynamic shape than the open tip bullets, and also has a tendency to flatten the projectile when it hits a target. The bullets don’t open up as dramatically as a hollow point round, but it’s still an improvement. Especially where hollow point rounds are illegal.

But if you’re looking for a type of bullet that’s a really good hunting round, there’s something far better out there than a soft point bullet.

Ballistic Tip

Nick Leghorn for TTAG

How do you get the benefits of a hollow point with the long range accuracy of a FMJ? By adding a small piece of plastic. “Ballistic tip” bullets feature an exaggerated opening in the tip of the copper jacket to allow the bullet to expand upon impact. But that hole is covered by a cone-shaped piece of plastic that allows the bullet to perform as if it were a FMJ. It’s a pretty nifty design, and one that I use to great effect in my hunting ammunition.

Other Bullet Types

While a lead core is the standard for bullet construction, there are some other interesting designs that are purpose-built for specific roles. Here are a few:

Frangible — These bullets are made out of compressed granules of copper, and are designed to shatter upon impact with a hard surface. They are used mainly as training ammunition in shoot houses, where over-penetration is a serious concern.

Standard Copper — Copper-only bullets are extremely effective and they’re available in a variety of bullet types and weights. Eliminating the lead core keeps more lead out of the environment and some states have mandated their use for hunting.

Total Metal Jacket (TMJ) — Lead core bullets that are totally encased in copper to reduce lead exposure. Some indoor ranges require this as it reduces the amount of lead particles in the air.

Jacketed Flat Nose — A jacketed bullet usually used in lever-action rifles

Steel Core / Armor Piercing — The lead core is replaced with a solid dart-shaped chunk of steel, designed to pierce body armor and some thinner-skinned vehicles. This can ruin steel targets, and cause ricochet hazards if used improperly.

Tracer — Bullets are treated with a chemical (usually phosphorus) that burns as the round flies downrange. This allows shooters to see where their bullet flies, but also keeps burning after the projectile lands and can be a fire hazard.

That’s a good introduction to the different types of rifle bullets and why they’re used. If you’d like more information on this or other firearms topics, let us know.

The article mentions solid copper, but just refers to it a little different, so you just have to read the article instead of skimming.
“Standard Copper — Copper-only bullets are extremely effective and they’re available in a variety of bullet types and weights. Eliminating the lead core keeps more lead out of the environment and some states have mandated their use for hunting.”

I was at the range one day, and the guy next to me had been invited to a hunt and was trying all copper ammo for the first time. .22LR I think. He said the accuracy was horrible. I doubt that there is anything inherently bad about pure copper, but be forewarned.

I knew someone who tried to use OTM ammunition (.308 155g Palma Match) for hunting. I told him the results will vary. And they did. Some opened nicely and dropped several pigs. Others went like FMJs and punched straight through.

Having previously hunted with FMJs, I can tell you shot placement is paramount. With pigs I would aim for the shoulders or the front leg. The pigs wouldn’t run very far with a broken front leg.

And a friend of the person using OTM rounds would use varmint projectiles through his .243 on pigs. He chose them for the accuracy off the bench. The result was shallow cratering wounds with no real internal penetration. All the pigs had to be put down with a .22 to the back of the head.

My choice on the first trip were a 6.5×55 M96 using PMC 139g SP. Everything was a one-shot-stop. The next trip was using a 8×57 with 170g RNSPs. Also giving one-shot-stops.

Shattering is a better term for what happens to a lead projectile upon impact, but not in a way we usually think shattering refers to. As the lead projectile is deformed upon impact, miniscule amounts of the projectile begin to seperate from the core projectile. Lead, because of its chemical makeup, shatters less than some other materials, which is why the spent slug is typically found, but if it’s weighed, there’s usually a significant difference in the weight of deformed projectile v. an intact projectile.

First, there are lead bullets, which can be “hard cast” or “soft.” Total lead bullets are often used in older cartridges which were designed from their inception to use cast lead bullets – eg, the .45-70, and similar 19th century cartridges. Some handgun cartridges also use solid lead bullets (eg, .45 Colt, .44-40, .38 Special), and most .22LR rounds are solid or hollow point lead, with perhaps only a minor flashing of copper or brass on top of the lead. “Hard cast” lead bullets will not deform much on impact with game or in a defensive use. Shooters often prefer hard cast because they leave less lead in the barrel to clean out later. “Soft” lead bullets will deform, often markedly so. They’ll also load up your bore if you allow them to do so.

Lead bullets might have a gas check on their base to allow for higher pressures/velocities.

Second, there are the brass/bronze solids meant for deep penetration on dangerous game, such as Cape Buff. These will be made by Woodleigh and others, perhaps rolled into ammo by such outfits as Kynoch. These are made to penetrate quite deeply through bone and tough hides without fragmentation or loss of mass.

Third, while varmint rounds are often lead-cored jacketed bullets, their cores are sometimes sintered metal powder inside a thin, ductile copper jacket as opposed to lead wire (or poured lead) inside a thicker copper jacket. Varmint bullets might resemble ballistic hunting bullets, but the semblance is purely cosmetic, as their interior construction is very different.

The idea of a varmint bullet is that as soon as this bullet hits something, the bullet literally explodes, dumping all its kinetic energy into a very small zone of penetration. These are used on small, thin-skinned varmints like ground squirrels and prairie dogs. If someone misses their target at a shallow impact angle, a heavier-jacketed ballistic/FMJ/etc bullet could ricochet quite a long ways; but the varmint bullet typically explodes instantly upon even a glancing impact with the soil, resulting in the bullet being scattered behind the point of impact by (typically) no more than about 10 to 20 yards.

Thank You for the correction…. JHP’s don’t just STOP…. they can easily hit secondary and even tertiary “targets”… Newbies NEED to hear the TRUTH about overpenetration. You can really ruin your day by hitting something beyond your intended target. Depending on caliber you could do serious, possibly fatal damage. ALWAYS check what’s beyond your target because you ARE liable for where your bullet goes, and what it destroys.

I need a bullet that works as well for Serial Deer as it does for Bigfoots. I could use shotgun slugs, I’m sure they’d work for both, but at the extreme range that most Bigfoots are shot, I couldn’t use a shotgun, me and slugs are done at about 896 yards. I’ve tried a scope on the shotgun, however after about a dozen shots the barrel gets hot, then the duct tape comes loose and the scope falls off

Question for you shooters out there: Is there any benefit to shooting boat-tail bullets in a high-power rifle? My Savage 112SSVB shoots 190gr speer factory loads to one ragged hole at 100 yards, even with a cheap scope and non-accutrigger. Yet I was always taught that the anti-drag benefits of the boat-tail only start when the bullet drops below supersonic, which is well past 1000 yards. What do you think?

Boat tail bullets give an improved performance over flat-base Spitzer bullets when the bullet is going trans-sonic – say, Mach 1.0 down to Mach 0.85 or so. The “boat tail” helps “fill up” the void behind the bullet – but only if the angle of rebate is between 7 to 9 degrees (If my memory serves on this bit of trivia). Too extreme of a rebate angle on the boat tail and turbulence develops behind the bullet, just not in quite as an abrupt manner as it would for a flat-base Spitzer.

Here’s a practical application you can observe: Have you ever seen those “chutes” that are now attached to the rear of trailers on 18-wheelers on the highway? It forms a hollow box behind the trailer doors? That’s doing for the trailer what the boat tail does for the bullet – it’s trying to “fill up” the void behind the trailer’s flat rear surface, reducing drag and increasing fuel mileage.

Basic net:net is that boat tails are one feature that helps reduce he drag on a bullet. If your bullet is doing one-hole groups, I’d say keep using it – why mess with success?